Cadastral point tolerance checks
Trimble Access provides the ability to check measured or staked out points have been double‑tied to ensure they meet the cadaster regulations for being within tolerance. To date, this feature has been developed to meet cadaster regulations in Switzerland. If your country uses the same cadastral tolerance checking rules you may be able to use this functionality in your own region.
To use this functionality in Trimble Access you will need to add an XML file to the Trimble Data\System Files folder. The XML file defines the cadastral codes and specifies the different tolerance requirements for the type of point being measured or staked. The sample CadastralTolerances.xml file is available to help you get started.
Once you have enabled cadastral tolerance checking in the job, the Trimble Access software automatically checks the tolerances for cadastral points in the job when you stake a point or compute an average of two or more points. The status of each cadastral point is displayed on the map and is summarized in the job screen.
To set up the controller so that Trimble Access automatically checks tolerances for cadastral points in the job:
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Download the sample CadastralTolerances.xml file from the Configuration files page.
The sample CadastralTolerances.xml file provides example codes and includes notes that explain how the file works, and what can be configured. For more information, see Cadastral XML file setup.
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Using a text editor, configure the CadastralTolerances.xml file to use your codes and tolerance values.
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Set up your own codes and make sure the tolerance values in the CadastralTolerances.xml file are correct, or modify them to match the tolerance values required.
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Make sure the codes in the CadastralTolerances.xml file are correctly assigned the classification name that matches the tolerance values required, and modify them as needed.
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Copy the CadastralTolerances.xml file to the Trimble Data\System Files folder on the controller.
The XML file must be named CadastralTolerances.xml for automatic cadastral point tolerance checking to occur.
For each job that you want to enable automatic cadastral tolerance checks:
- Tap and select Job.
- Tap Properties.
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In the Notes field of the Job properties screen, enter the appropriate cadastral Class name (for example TS2) for the cadastral points in the job. All cadastral points in the job must use the same cadastral class.
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Tap Accept.
The job details panel now includes the Cadastral summary, which shows a color-coded summary of cadastral points in the job.
The Cadastral summary in the Job details panel in the Jobs screen shows the number of cadastral points in the job, by status.
The map provides immediate feedback on the status of cadastral points:
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Green: The point is double‑tied and the averaged measurement is within the standard error values defined in the CadastralTolerances.xml file.
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Orange: Because the point is not double-tied (it has only a single measurement), the tolerance is unknown.
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Red: The point is double-tied and the averaged measurement is outside the standard error values defined in CadastralTolerances.xml file.
The display of the colored icons is prioritized so that red is displayed on top of orange, which is displayed on top of green. This means that points out of tolerance or not double‑tied are more visible at any zoom level.
For any point for which the Code field specifies a cadastral code defined in the CadastralTolerances.xml file, the Trimble Access automatically performs cadastral tolerance checking when:
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staking the point
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when computing an average, such as:
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when you compute an average using the Compute average function.
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when the software detects a duplicate point and from the Action drop-down list you choose to average the points.
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The computed polar horizontal and vertical standard errors for the staked or averaged position are compared with the standard error values recorded for that cadastral code in the CadastralTolerances.xml file, and shown in the Tolerance check group box of the As-staked deltas or the Compute average screen.
The color of the point on the map changes to indicate the status of the cadastral point.
Some cadastral regulations may require that each measurement is "independent"for double-tied cadastral points. For conventional surveys, you may be able to achieve this using a different station setup or using the Taped distances feature. For GNSS surveys, you can use the SV subset feature to divide all tracked satellites into two subsets with an even spread throughout the sky, and use one subset to measure and then the other subset to remeasure the point using independent occupations.